06 December 2009

Nightingale x healthcare x visualizing data

Some of you have seen this already:

It's a dynamic visualization that GE put together with Ben Fry and Seed Media to show the costs associated with different chronic illnesses. It's a Processing file, so I recommend heading over to The cost of getting sick to play around with it a little.

When I brought this partnership up with my friend Mike this week, he pointed me toward this:

Here's where stuff gets amazing: that was hand-drawn in 1858 by Florence Nightingale. Eighteen fifty-eight. EIGHTEEN. fifty-eight. Mike went on to tell me that in addition to being a nurse, Nightingale was a pretty brilliant statistician. She actually invented this kind of chart (it's called a polar area diagram). Wow!! Here is part of it in a little more detail:

It shows the causes of death in military hospitals during this time:

The area of each coloured wedge, measured from the centre as a common point, is in proportion to the statistic it represents. The blue outer wedges represent the deaths from: preventable or mitigable zymotic diseases, or in other words contagious diseases such as cholera and typhus. The central red wedges show the deaths from wounds. The black wedges in between represent deaths from all other causes. Deaths in the British field hospitals reached a peak during January 1855, when 2,761 soldiers died of contagious diseases, 83 from wounds and 324 from other causes making a total of 3,168. The army's average manpower for that month was 32,393. Using this information, Nightingale computed a mortality rate of 1,174 per 10,000 with 1,023 per 10,000 being from zymotic diseases. If this rate had continued, and troops had not been replaced frequently, then disease alone would have killed the entire British army in the Crimea.

The way this chart came about began with how Nightingale saw hospitals being run. Conditions were unsanitary (to put it lightly), and she wanted to see reform in the entire hospital system. Being a woman during this time made it pretty hard to get heard, so she decided to observe and write down the causes of death she was exposed to over a period of time through her own record-keeping system to see if she could make a convincing case for reform. Eventually she had amounted so much data that she was seeing patterns in (too many deaths that could have been prevented, essentially (the blue wedges)) that she did some calculations and finally did have a solid case. In brief, that mortality rates could decrease if some changes were made within city and military hospitals.

Nightingale needed a concise way to present this data and clearly make her point, so she told its story visually through the polar area chart to ensure that non-statisticians (public officials, in this case) could understand it. The rest of the story is pretty storybook: Her wishes for a formal investigation were granted in May 1857 and led to the establishment of the Royal Commission on the Health of the Army. Nightingale hid herself from public attention, and became concerned for the army stationed in India. In 1858, for her contributions to army and hospital statistics Nightingale became the first woman to be elected to be a Fellow of the Royal Statistical Society. [src]

Everyone around me has been nerding out on telling compelling stories from heaps of numbers for a while now, and it was pretty great to find this (eighteen. fifty. eight.) and learn about one of the earliest processes and motivations behind graphical representations of statistics. Neat, huh?